What are the major differences?The major difference between IPv4 and IPv6 is the number of IP addresses.
There are 4,294,967,296 IPv4 addresses.

In contrast, there are 340,282,366,920,938,463,463,374,607,431,768,211,456 IPv6 addresses.
The technical functioning of the Internet remains the same with both versions and it is likely that both versions will continue to operate simultaneously on networks well into the future.

To date, most networks that use IPv6 support both IPv4 and IPv6 addresses in their
networks.